Mutually constrained inversion (MCI) is a process in which two distinct data sets are inverted to produce two closely related models. Time domain electromagnetic (TEM) and electrical resistivity are two methods, that measure the same fundamental property, resistivity, but have different sensitivity and will not necessarily respond to the earth in the same manner. MCI has many of the properties of joint inversion, the process where two datasets are inverted to produce one model. Poorly resolved parameters are enhanced and invisible layers can be seen. However MCI is more robust, the two resulting models can be independently evaluated, and the best resolved parameters used in the interpretation. The approach is illustrated first on synthetic data. The MCI is used to resolve incompatibilities produced when the resistivity sounding is distorted with near surface inhomogeneities, a static shift, without the need of a special parameter that cannot be measured. A field study demonstrates how a resistive layer, which is important in aquifer characterization, that is either inconsistently detected or unresolved in the separate time domain and resistivity datasets, is well delineated with the MCI.
- Programområde 2: Vandressourcer